BACKGROUND:
Ingestion of radiopaque markers (ROM) is frequently used to determine colonic transit in chronic constipation. Although ≥20% of retained markers at 5 days defines slow-transit constipation, some clinicians use the number of retained markers to determine disease severity.

METHODS:
We assembled a cross-sectional cohort of patients presenting for evaluation of chronic constipation who underwent transit testing by ROM and completed validated symptom severity and quality-of-life (QOL) measures. We performed a correlation analysis to determine whether there was an association between number of retained markers and symptom severity and QOL.

CONCLUSIONS AND INFERENCES:
Among patients with chronic constipation, number of retained markers on a ROM colonic transit study does not correlate with measures of symptom severity or QOL. Clinicians should be cautious about overinterpreting ROM transit testing.